title: Prognostic effect of sarcomatoid dedifferentiation in patients with surgically treated renal cell carcinoma: a matched-pair analysis.
abstract: BACKGROUND
  The aim of this study was to assess the prognostic relevance of SD in patients with RCC.
  
  
  METHODS
  Among 8126 RCC patients surgically treated at 12 academic centers (members of the Collaborative Research on Renal Neoplasms Association [CORONA] project), 316 patients (3.9%) had SD with sarcomatoid areas comprising at least 10% of the tumor tissue. After propensity score-based matched-pair analysis, 281 with and 281 matched RCC patients without SD remained available for direct comparison of cancer-specific survival (CSS). Median follow-up was 36.5 months (interquartile range, 15-82). Uni- and multivariable Cox proportional hazards regression analyses were performed to assess the prognostic value of parameters.
  
  
  RESULTS
  In univariable analysis, there was no difference in CSS between patients with or without SD (1 and 5 years CSS, 79% vs. 83% and 59% vs. 64%, respectively; hazard ratio, 1.21; P = .16). Multivariable analysis in patients with SD identified metastatic dissemination at the time of surgery, pT-stage, nodal status, and tumor size as independent predictors of CSS. This study was limited by its retrospective multicenter design and lack of central histopathological review.
  
  
  CONCLUSIONS
  Sarcomatoid dedifferentiation was not an independent predictor of CSS in surgically treated RCC patients in the present matched-pair series. Because pathology reports form the basis on which study specimens are selected for further studies, which are clearly needed to advance our understanding of the prognostic value of SD in RCC, it is imperative that pathologists reliably report on absence or presence and the estimated percentage of a coexisting sarcomatoid component.
authors.affiliation: Department of Urology, Ludwig-Maximilians-University Munich, Klinikum Grosshadern, Munich, Germany. Electronic address: sabine-brookman-may@web.de.
authors.forename: Sabine
authors.initials: S
authors.lastname: Brookman-May
authors.forename: Matthias
authors.initials: M
authors.lastname: May
authors.forename: Shahrokh F
authors.initials: SF
authors.lastname: Shariat
authors.forename: Richard
authors.initials: R
authors.lastname: Zigeuner
authors.forename: Thomas
authors.initials: T
authors.lastname: Chromecki
authors.forename: Luca
authors.initials: L
authors.lastname: Cindolo
authors.forename: Luigi
authors.initials: L
authors.lastname: Schips
authors.forename: Ottavio
authors.initials: O
authors.lastname: De Cobelli
authors.forename: Bernardo
authors.initials: B
authors.lastname: Rocco
authors.forename: Cosimo
authors.initials: C
authors.lastname: De Nunzio
authors.forename: Andrea
authors.initials: A
authors.lastname: Tubaro
authors.forename: Bogdan
authors.initials: B
authors.lastname: Feciche
authors.forename: Ioan
authors.initials: I
authors.lastname: Coman
authors.forename: Michael
authors.initials: M
authors.lastname: Truss
authors.forename: Sascha
authors.initials: S
authors.lastname: Pahernik
authors.forename: Manfred P
authors.initials: MP
authors.lastname: Wirth
authors.forename: Stefan
authors.initials: S
authors.lastname: Zastrow
authors.forename: Orietta
authors.initials: O
authors.lastname: Dalpiaz
authors.forename: Fabian
authors.initials: F
authors.lastname: Fenske
authors.forename: Raphaela
authors.initials: R
authors.lastname: Waidelich
authors.forename: Christian
authors.initials: C
authors.lastname: Stief
authors.forename: Sven
authors.initials: S
authors.lastname: Gunia
mesh_terms: D000368:Aged; D002292:Carcinoma, Renal Cell / Q000401:mortality / Q000473:pathology* / Q000601:surgery; D054337:Cell Dedifferentiation; D005260:Female; D006801:Humans; D007680:Kidney Neoplasms / Q000401:mortality / Q000473:pathology* / Q000601:surgery; D008297:Male; D016555:Matched-Pair Analysis; D008875:Middle Aged; D011379:Prognosis; D012189:Retrospective Studies
keywords: Cancer-specific mortality; Histological subtype; Nephrectomy; Prognosis; Propensity-score matching